Yarn-package winding machine



March 28, 1967 s. FURST YARN-PACKAGE WINDING MACHINE 5 Sheetsheet 1 Filed July 21, 1964 s. FURST 3,311,311

YARN-PACKAGE WINDING MACHINE March 28, 1967 5 Sheetsheet 2 March 28, 1967 s. FURST 3,311,311

YARN-PACKAGE WINDING MACHINE Filed July 21, 1964 5 Sheets-Sheet 5 United States Patent 3,311,311 YARN-PACKAGE WINDING MACHINE Stefan Fiirst, Monchen-Gladbach, Germany, assignor to Walter Reiners, Monchen-Gladhach, Germany Filed July 21, 1964, Ser. No. 384,211 Claims priority, application Germany, July 22, 1963, R 35,736, R 35,737 8 Claims. (Cl. 242-18) My invention relates to winding machines for producing relatively large and cross-wound yarn packages, such as cheeses and cones, from smaller coils, such as bobbins or spinning cops, and has for its principal object to facilitate and improve the winding operation with respect to the commencement of a new yarn package being wound upon a tubular core.

Regardless of whether in such machines the take-up spool for a yarn package is driven directly or by entrainment at its periphery, trouble is often encountered when a yarn package is being started. As the initial turns of yarn are wound upon a still empty core, socalled Wild turns may occur on account of the fact that the usually smooth core surface offers too little frictional adherence to the yarn which, as it runs onto the core, is simultaneously subjected to considerable lateral pull by the yarn-guiding member which reciprocates the on-coming yarn along the core in order to produce the crosswise helical winding layers of the package. Under these starting conditions, a cross-wound layer of yarn cannot be formed without shoving the initial turns or layers together. The wild turns manifest themselves upon subsequent dyeing of the yarn by irregular coloring and also interfere with orderly unwinding the packages.

It is an object of my invention to avoid such shortcomings and to provide for increased frictional adherence of the first winding turns or layers upon the takeup core during the initial winding stage of a package.

Another object of the invention is to achieve the justmentioned improvement with the aid of relatively simple devices which are readily applicable not only in new winding machines but also as an addition to existing machines.

To achieve these objects and in accordance with a feature of my invention, I provide a yarn-package winding machine of the above-mentioned type with controllable yarn tension means which increase the yarn tension for a limited, short interval of time during the starting interval of a package winding operation, thus providing for increased frictional adherence of the yarn turns to the core to be filled with layers of yarn turns.

The temporary increase in yarn tension may be effected by applying a temporary additional loading to the yarn brakes with which such machines usually are equipped for the purpose of keeping the travelling yarn in taut condition. In some cases, however, it is preferable to provide for temporarily increased yarn tension by providing the machine with additional tensioning devices.

The actuation of the yarn tensioning means may be controlled in dependence upon the pulse or signal which initiates the winding operation, regardless of whether the take-up spool of the machine is driven directly, i.e. through a spool shaft, or whether the take-up spool is driven by means of frictional entrainment at its periphery. According to a more specific feature of the invention, the switching pulse or signal for starting the winding operation, released for example by a control lever, acts upon an electrical or mechanical time-delay relay to apply an additional load upon a yarn brake, causes the actuation of the above-mentioned additional yarn tensioning means by energizing suitable electromagnets or actuating mechanical controls.

According to still another feature of the invention,

ice

relating to winding machines in which the take-up spool is journalled in a pivotally mounted frame structure and driven peripherally by frictional entrainment, it is particularly simple to control the operation of the yarn tensioning increasing means in dependence upon the angular position of the spool-journalling frame, namely so that the actuation of the yarn tensioning means occurs only when the journalling frame moves to the angular position in which it places the journalled spool core into frictional engagement with a driving drum.

Tubular cores, even if of the same kind, may differ from each other considerably as to diameter or wall thickness. For that reason, the interval of time in which a tension increasing device according to the invention, as mentioned above, remains effective may vary with different cores so that the number of yarn layers wound with increased yarn tension and/or increased contact pressure between take-up spool and driving drum, may also vary. It is another object of my invention to minimize such differences.

According to another feature of the invention, therefore, the device for temporarily increasing the yarn tension during the initial stage of a package-winding operation is made dependent upon a given interval of time having a predetermined constant duration.

According to a more specific feature, the interval of increased tension is determined by mechanical, electrical or other time-delay relay means.

The invention is of particular advantage in conjunction with yarn-package winding machines equipped with automatic devices for the exchange of a full take-up spool by an empty core. In such machines, the auxiliary device for temporarily increasing the yarn tension during initial winding operation is preferably actuated under control by the above-mentioned time delay relay in dependence upon the performance of the spool exchanging mechanisms upon insertion of a new spool core. Such embodiments of the invention are particularly well applicable in multi-station winding machines in which a number of individual winding stations, each having a wind-up drive, are serviced by a single spool-exchanging servicing unit. In winding machines wherein each individual Winding station has its own automatic means for exchanging the takeup spools, it is particularly simple and advantageous to have the operating interval of the tension-increasing device controlled by the automatic spool exchanging means.

The above-mentioned and other objects, advantages and features of my invention, said features being set forth with particularity in the claims annexed hereto, will be apparent from, and will :be mentioned in, the following with reference to embodiments of winding machines according to the invention illustrated by way of example on the accompanying drawings, in which:

FIGS. 1 and 2 show schematically the two different machines by respective side elevations.

FIG. 3 shows more in detail a partly sectional side elevation of a third embodiment; and

FIGS. 4 to 7 show respectively four control cams which form part of the machine illustrated in FIG. 3.

According to FIG. 1, the frame structure 1 of the machine carries a supply coil 2 from which the yarn F passes through yarn-guiding members 3, 4 and through a brake 5 of the disc type onto a guiding drum 6 from which it runs onto the core 7 of the take-up spool. The core is revolva'bly seated on a journalling frame 8 which is pivotally mounted on the frame structure 1 at 8'. The shaft 6' of the drum 6 is driven at constant speed. During winding operation, the core ofthe take-up spool rests upon the periphery of the drum 6 and is driven at constant peripheral speed by frictional entrainment. As the yarn is thus wound upon the core, the growing yarn package remains peripherally entrained and hence continues rotating at constant peripheral speed. It will be understood that the yarn guiding drum 6 is provided with the conventional guiding groove which forms a loop that extends peripherally about the drum as well as longitudinally of the drum and is closed upon itself so as to impart to the oncoming yarn a reciprocating motion lengthwise of the take-up spool with the result of producing the desired cross-wound package of yarn. As the first few turns or first layers of yarn are being wound upon an empty core, the friction on the core surface may be too slight for securely holding the yarn in the proper position, so that the reciprocating motion of the oncoming yarn is apt to disarrange the first turns. By virtue of the invention, such dishevelling of the yarn and the resulting deficiencies of the yarn package are eliminated.

For this purpose, a rod 9 is linked to the journalling frame 8 and is straddled by a hook 10 which passes through a guide 11 and is linked to an arm 12. The pivot shaft 13 of arm 12 carries a switch lever 14 which, when depressed by the attending person, closes an electric circuit (not shown) that sets the drive for the drum 6 in operation and thus commences the winding operation. The lower end of the rod 9 is opposite a substantially horizontal rod 15 which passes through a guide 16 and is linked to one arm 17 of a three-arm lever whose other arms are denoted by 18 and 19. The lever arm 18 is connected with a damping and time-delay device 20 which, in the illustrated embodiment, is designed as a dashpot filled with oil. The lever arm 19 abuts against the top of a helical compression spring 25 acting upon the top disc of the yarn brake 5.

In this embodiment, the increase in frictional adherence of the first yarn layers to the empty spool core is efiected by temporarily increasing the yarn tension with the aid of the spring-loaded brake for a short interval of time, commencing with the starting of the winding operation. For this purpose, the yarn brake 5 is additionally loaded under control by the pulse or signal that initiates the winding operation. This takes place as follows.

The rod 9 linked to the spool journalling frame 8 has its lower end located opposite the rod 16 only when the core placed onto the driving drum 6 is still empty. When the switching lever 14 is being depressed for placing the winding station in operation, the arm 12 turns clockwise to the right, and the hook turns the depending rod 9 also to the right so that the rod is pushed to the right and turns the lever 1748-19 clockwise a slight amount. The lever arm 19 thus imposes through spring 21 an additional load upon the tensioning brake 5. Simultaneously the lever arm 18 pulls the piston 22 of the damping device slightly in the upward direction. As soon as the switching lever 14 is released by the attending person, the pressure imposed by rod 9 upon rod 15 ceases, and the lever 171819 is turned counterclockwise by the force of spring 21. This occurs at a speed determined by the delaying action of the damping device 20. As soon as the spring 21 reaches its relaxed length, the additional loading of the tensioning brake 5 is eliminated, and the increase in yarn tension is ended.

In FIG. 2, components corresponding to those of the machine shown in FIG. 1 are denoted by the same reference numerals respectively. According to FIG. 2, the temporary increase in yarn tension during starting of a winding operation is controlled in dependence upon the angular position of the spool journalling frame 8.

For this purpose, the journalling frame 8 carries a permanent magnet 23 whose magnetic field can become effective upon a magnetizable portion 24 of the machine frame structure 1 when the journalling frame 8 is in the lowermost position where it places an empty core upon the driving drum 6. A rod 25 has one end linked to the journalling frame 8 and its other end joined with one arm of a lever 26 pivoted to the frame structure 1 at 26. Only when the spool core 7 is empty or almost empty can the right-hand arm of lever 26, under control by the rod 25, penetrate between two fixed yarn-guiding members 4 in order to deflect the yarn F and subjecting it at this location to increased friction, thereby increasing the yarn tension normally set by a disc-type tensioner 5.

It will be understood that for the additional and shortlasting increase in yarn tension in accordance with the invention, other yarn-tensioning means than those illustrated may be used, for example yarn brakes of the claw type, electromagnetic yarn brakes and others, the control of these tensioning devices being effected in dependence upon any one of a number available other criteria peculiar to the starting interval of a package winding operation, such as the length of yarn wound upon the core, the number of yarn layers wound upon the core, or a constant interval of time.

While the illustrated embodiments are equipped with rotating yarn guiding drums, it is obvious that the reciprocating levers or other mechanisms are also applicable for reciprocating the oncoming yarn along the take-up spool, the particular type or design of the yarn reciprocating means being unessential to the invention proper.

FIGS. 3 to 7 relate to a machine in which each winding station is provided with its own mechanism for automatically replacing a full take-up spool by an empty core and which is provided with two auxiliary devices, one serving to increase the contact pressure between take-up spool and driving drum, and the other to temporarily increase the yarn tension. Both auxiliary devices are active for securing an accurate winding of the initial turns or layers of yarn when a new package is being wound.

With the exception of the two auxiliary devices and the components serving for their control, the machine of FIGS. 3 to 7 is similar to the one more fully illustrated and described in my- Patent 3,092,340, to which reference may be had if desired with respect to details not essential to the present invention.

The yarn F coming from the supply coil A passes through a yarn tensioning brake 260 and the yarn guiding drum 22 onto the take-up spool 21. The tubular core 191 of the spool 21 is revolvably clamped in the journalling frame 20 pivotally mounted at 140 to the machine frame structure 201. Linked to the journalling frame 20 is a damper rod 102 which carries a disc 103 engaging a lever 104. The lever is spring-biased for compensating the weight of the journalling frame 20. A segment rotatable about the pivot of the lever 104 has an elongated slot engaged by a pin of lever 104 so that the segment 105 is entrained by the lever 104 when the latter moves counterclockwise from the illustrated position. Engageable with the segment 105 is alever 106 which during winding operation occupies the position 106' shown by dot-and-dash lines. However when the spool is filled and therefore the segment 105 is in the position illustrated, the lever 106 snaps to the full-line position under the action of a pull spring 14 1. In this position, an arm 107 of lever 106 places a nose 109 beneath a normally oscillating lever 45 and thus arrests the lever 45. Oscillating motion is imparted to the lever 45 by a rod 46 and causes the lever 45 to perform a continual testing movement or, as the case may be, to perform a swinging motion which serves for discontinuing the winding operation of the winding station.

When the lever 45 is arrested by the nose 109, a control lever 31 on which the lever 45 is pivotally mounted, is fixed in a position in which it shifts a friction roller 25 to the illustrated position away from a driving roller 16 and away from the guiding drum 22. During winding operation the friction roller 25 forms a transmission between the roller 16, rotating at constant speed, and the guiding drum 22, thus driving the drum 22 at constant speed for the purpose of transmitting the driving motion to the take-up spool 21. When the friction roller 25 is shifted, under control by lever 31, to the illustrated position, the winding motion is stopped, so that the full yarn package can be removed and substituted by an empty core.

Ioined with the lever 165 is another arm 142 which is linked by a rod 143 to a detent 144 (FIGS. 3, 4) and to a control pawl 139. When the lever 11% is in the full-line position shown in FIG. 3, the detent 14-4 and the pawl 89 are moved to coactive positions relative to a control cam 145:: (FIG. 4). The detent 1 1 1 is engageable with a catch recess 139 of cam 145a and, when moved away from the cam, releases it for a single full rotation. The cam 145a forms part of a cam group mounted on a shaft 146 which revolves continuously at constant speed as long as the machine is in operative condition. A frictional slip clutch (not shown) connects the cam group with the shaft 146 but can only become eifectve to turn the cam .group when the detent 144 moves to releasing position.

The cam group 145 (FIG. 3) further comprises three cam discs 145b, 1450, 145d (FIGS. 5 to 7). As seen in FIG. 3, the cam 145a lies in front. While the catch recess 139 cooperates with the detent 14- 1- in the abovedescribed manner, a dog pin 188 on cam 1 15:: is engageable with the control pawl 189. Next behind cam 1451 is the cam 1452). It cooperates with a follower lever 148 (FIG. 5) which acts on a control rod 142 (FIG. 3). A spring 150 seated on rod 149 biases the follower lever 148 toward engagement with the cam 14512. Located next behind the cam 1 15b is the cam 1450. It cooperates with a bell-crank lever 152 (P16. 6) through a roller 152a journalled on the lever 152. Located at the rear of the entire group is the cam 145d. It cooperates with a dog pin 174 of a swing lever 168 (FIGS. 3, 7) pivoted to the machine fram structure 231 on a pivot pin 167 which is also common to the follower lever i148 and the bellcrank lever 152.

The control rod 149 is linked to a lever arm 151 forming part of the journalling frame 21). The bell-crank lever 152 is connected by a linking rod 153 with a lever 154 which is rotatable about the pivot 141) of the journalling frame and carries on its opposite end a core magazine 155. The outlet of the magazine is normally closed by a flap 156 biased by a spring 157. The flap can open to such an extent that an individual core S can be removed from the magazine. To permit this, the magazine 155 is open at its lower end at both axial ends of the core located in the lowermost position. The magazine-carrying lever 154 is provided with a set screw 1158. When the magazine moves downward, the screw 15S acts upon a pawl 159 biased by a spring 1611. The pawl 159 is pivotally mounted on the journalling frame 29 for rotation about a pivot axis 1e1. A stop 162 limits the pawl movement.

The device mounted on the journalling frame 20 for revolvably holding the spool core may be designed in accordance with the one shown in Patent 3,092,340 (FIG. 15); or in Patent 3,131,885. In such a holding device, the rotation of a control ram 163 (FIG. 3) causes an axial displacement of a dowel for clamping the tubular spool core. The arm 163 carries a catch pin 164 engageable with a hook 165 of the pawl 159 when the pawl is turned counterclockwise by means of the set screw 153 to its limit position against the stop pin 162. A spring 166 acts upon the arm 163 and tends to rotate it counterclockwise to thereby clamp the spool core in the holder device.

As mentioned, the follower pin 174 of swing lever 163 is kept in engagement with cam 1450. by the spring 175. When the arm 1-38 is permitted by cam 145d to swing counterclockwise under the action of spring 175, the two horns 172 of the entrainer 169 move toward the left and snap under the ends of the core 191 upon which the completed yarn package is wound. in the left-hand position of the swing arm 168, the lower end of one of the horns 172 engages the pin 164 on the actuator arm 163 and turns the arm 163 counterclockwise (toward the left) until the hook 165 of pawl 159 catches behind the pin 1 6 In this position, the clamping device for journalling the take-up spool is open so that the completed spool drops into a supporting sheet 180 and, during the next following return stroke of the entrainer 16 9 toward the right, is taken along to the dot-and-dash position 21'.

T e swing arm 168 is provided with 2. lug 17 6 for cooperation with a yarn-deflector 177 which has an arm provided with a yarn-guiding portion 132. The deflector 177 is rotatable on a vertical pivot pin 181 which is secured to plate 1 8i) attached to the stationary frame structure of the machine. A spring 17 9 mounted on pin 181 biases the deflector 177 to turn the yarn-guiding portion 182 to the rear (i.e. in the direction away from the observer in FIG. 3) when the swing arm 168 turns counterclockwise. When thereafter the swing arm 168 returns clockwise to the end position illustrated in FIG. 3, the yarn-guiding end 18% returns to its illustrated forward position and then entrains the yarn from the normal path to a position laterally of the completed yarn package so that the yarn end is placed out of the way and cannot interfere with the insertion of an empty core from the magazine 155.

The supporting tray or sheet member 1-80, has a concave portion to receive the take-up spool when the latter, during the above-described dotting operation, is released from the spool holder. When thereafter the filled spool is conveyed by the entrainer 169 to the position 21', it again rests in a concave portion of sheet member 181 thus being prevented by the intermediate bulge or ridge from inadvertently rolling back to the range of the Winding operation.

The various components of the machine are mounted on the above-mentioned frame structure 2111 which also comprises transverse connecting bars 262, 203 and 204 of tubular shape.

The frontal cam of the cam group 145 carries a dog pin 2513 (PEG. 4) which, shortly before the cam group terminates its rotation, actuates a bell-crank lever 251 (FIG. 3) pivoted at 253 and biased by a pull spring 252 toward the position shown in FIG. 3. The lever 251 is linked to a rod 25:? passing through a guide 255. Mounted on the damper rod 102 is a conical member 256 which is opposite the left end of rod 254- and only slightly spaced therefrom when the journalling frame is in the lowered position shown schematically at T. The corresponding lowermost position of the conical member 256 is shown by dot-and-dash lines. The conical member 256 can glide longitudinally on the damper rod 102, but its longitudinal displacement is limited upwardly by a shoulder ring fastened to the rod and downwardly by a compression spring abutting against another shoulder ring. Linked to the other arm of the bell-crank lever 251 by means of a connecting rod 257 is a lever 258 which has a downwardly directed arm abutting against a spring 25-9. The spring 259 forms part of the disc-type yarn brake 2 6i and permits subjecting the brake to additional loading in the manner described above with reference to brake 5 and spring 21 according to FIG. 1.

The above-described machine operates as follows.

When, during winding operation, the take-up spool 21 becomes increasingly filled with yarn, the diameter of the yarn package increases accordingly and causes the spool holder 21) to progressively turn counterclockwise (upward) about its pivot 146. The disc 163 on rod 192. participates in such upward motion. When the take-up spool is completely filled, the disc 103 has reached a position in which it causes the segment to release the cam-control lever 106 which then drops away from the periphery of segment 105 and turns counterclockwise under the action of spring 141. The lever 1% then shifts the linking rod 143 to the left and releases the detent 144 from cam 1455a. The cam set can now rotate together with the shaft 146 under the driving action of the slip clutch (not shown). During the single full revolution of the cam set, the swing arm 16 8 is turned counterclockwise by spring 175. The two horns 172 now enter beneath the core ends of the spool 21 so that these ends are placed into the curved portions 173 of the respective horns. The left end of one horn abuts against the pin 164 of the actuator on 163 and entrains it for rotation about the core axis in opposition to the force of spring 166. When the arm 163 is thus turned clockwise to its uppermost position, the nose 165 of pawl 159 catches behind the pin 154 and thereafter temporarily retains the actuator arm 163 in the opening position of the core-clamping device. Now the filled spool is free for the dofiing operation.

During the next following swinging motion of lever 168 to the right, the horns 172 of entrainer 1519 take the spool 21 along and place it into the concave portion at the right side of the supporting sheet 1%. In this position, the completed yarn package can remain until it is removed by hand or suitable conveying means within the period of time during which the next yarn package is being wound.

During the return motion of swing arm 153 from the spool-releasing to the illustrated position, the yam-guiding portion 182 of deflector lever 177 moves in the direction toward the observer of FIG. 3, due to the fact that the lug 176 of lever 168 abuts against the deflector 177. During this motion, the guide 182 seizes the yarn end F of the completed take-up spool and shifts the end forwardly (toward the observer). Now this yarn end is located in the vicinity of the yarn-guiding drum 22. at a point where subsequently the new, empty core is located, so that the yarn end is clamped between the new core 214 and the adjacent dowel member. While the yarn end is thus being placed in position for subsequent clamping, the cam-follower lever 148 is moved clockwise by cam disc 145b. This causes the spool-holder frame 2! to move downwardly to such an extent that the connecting line between the journalling axis of the spool holder and the pivot axis 140 reaches the lowermost position shown by a dash-and-dot line at T. At this time the laterally deflected yarn end from the completed spool 21 is located at a point where the next spool core will subsequently be clamped.

Now the cam 145e, acting through the follower lever 152 and the linking rod 153, moves the magazine lever 154 clockwise (FIG. 3) about its pivot 140, thus shifting the core magazine 155 downwardly until the lowermost core in the magazine 155 reaches the position S where the core touches the guiding drum 22. The set screw 158 on lever 154 hits against the upper end of the latch memher 159 and thereby releases the pin 1640f the arm 163. The arm 163, acting under the force of spring 166, now causes the lowermost spool core, still in the magazine 155, to be seized and clamped by the clamping device which simultaneously clamp the yarn as described above. During the subsequent upward motion of the magazine 155, the lowermost spool core, now clamped in the spool holder, passes out of the outlet opening of the magazine while temporarily forcing the flap 156 to the opening position. The flap 156 thereafter closes the magazine so that only the lowermost core is removed therefrom, and the magazine turns back to the stand-by position illustrated in FIG. 3.

After the spool exchange is thus completed, the winding section is ready to resume the next winding operation. The winder drive is switched on under control by the dog pin 188 'on cam 145a which acts upon the nose 189 of the detent 144 and shifts the linking rod 143 toward the right. This returns the cam-control lever 106 to normal operating position 106 shown by dot-and-dash lines. Due to the preceding downward motion of the spool holder 28, the weight-relieving lever 104 and the segment 105 have both turned counterclockwise about pivot 104:: so that 8 the upper end 'of lever 166 now rests against the peripheral contour portion of segment 105. Hence the force of spring 141 cannot turn the lever 106 to shift the rod 143, and a release of the detent member 144 is prevented.

Due to the just-mentioned motion of the cam-control lever 106 to the dot-and dash position, the oscillatable lever 45 is released from the latch hook 109 and can resume its oscillatory motion. This has the consequence that the drive-control lever 31 during its subsequent oscillating motion about its pivot acts through the control rod 41 to place the intermediate roller 25 into frictional engagement with the driving roller 16 and the guiding drum 22, so that the winding operation is again commenced. When the yarn begins to be wound up upon the new core, the yarn end F is torn, thus separating the yarn of the new spool from the spool previously completed. To aid in severing the yarn, a sharp edge may be provided at the yarn-guiding portion 182 of the deflector lever 177, so that the pull exerted by the winding operation upon the yarn causes it to be forced against the edge.

Before the cam group 145 has terminated its rotation, the dog pin 250 (FIG. 4) of cam 145a hits against the lever 251 and turns it counterclockwise about the pivot 253 in opposition to the force of spring 252 (FIG. 3). As a result, the left arm of lever 251 displaces the rod 257 and thereby the bell-crank lever 258 so as to increase the force of spring 25?. This increases the action of the yarn brake 26b and hence the yarn tension when starting the winding operation. At the same time, the right arm of lever 251. displaces the rod 254 against the conical member 256 now in the dot-and-dash position. As the end of rod 254 runs onto the conical surface, it imposes a downward force upon the damper rod 102 which frame 20 upon the spool core now being held against the rotating drum 22. Shortly before the cam group terminates the rotating motion, the lever 251 can return to its starting position so that the auxiliary devices cease to increase the yarn tension and relieve the increase in contact pressure between core and drum.

It will be understood that it is not always necessary to use both types of auxiliary devices but may suffice to employ either one of them alone.

To those skilled in the art it will be obvious upon a study of this disclosure that my invention permits of various modifications and hence can be given embodiments other than particularly illustrated and described herein, without departing from the esential features of the invention and within the scope of the claims annexed hereto.

I claim:

1. A. yarn-package winding machine comprising windup means for revolving a tubular core to wind the yarn thereupon, yarn guide means defining a yarn path and having a yarn reciprocating guide member adjacent said wind-up means for reciprocating the oncoming yarn along the core, controllable yarn-tensioning means disposed at said path for engaging the yarn and normally applying substantially constant tension thereto, said yamtensioning means having control means cooperating with said wind-up means for temporarily increasing the normally substantially constant yarn tension during initial winding of a package so as to increase frictional adherence of the initial yarn turns to the core.

2. A yarn-package winding machine comprising windup means for revolving a tubular core to wind the yarn thereupon, yarn guide means defining a yarn path and having a yarn reciprocating guide member adjacent said wind-up means for reciprocating the oncoming yarn along the core, yarn tensioning means having a controllable yarn brake engageable with the yarn on said path for normally applying substantially constant tension thereto, and control means cooperating with said brake and said windup means for controlling said brake to temporarily increase the normally substantially constant yarn tension Ll during initial winding of a package so as to increase frictional adherence of the initial yarn turns to the core.

3. A yarn-package winding machine comprising Windup means for revolving a tubular core to wind the yarn thereupon, yarn guide means defining a yarn path and having a yarn reciprocating guide member adjacent said Wind-up means for reciprocating the oncoming yarn along the core, a yarn brake engageable with the yarn on said path for maintaining normally constant tension in the yarn, an additional normally inactive yarn-tensioning device engageable with the yarn on said path, and control means connecting said tensioning device to said wind-up means for controlling said device to temporarily increase the yarn tension during initial Winding of a package for increased frictional adherence of the initial yarn turns to the core.

4. A yarnpackage winding machine comprising Windup means for revolving a tubular core to wind the yarn thereupon, a yarn guide means defining a yarn path and having a yarn reciprocating guide member adjacent said wind-up means for reciprocating the oncoming yarn along the core, controllable yarn-tensioning means disposed at said path for engaging the yarn and normally applying substantially constant tension thereto, said yam-tensioning means having control means cooperating with said wind-up means for temporarily increasing the normally substantially constant yarn tension during initial winding of a package so as to increase frictional adherence of the initial yarn turns to the core, said wind-up means comprising a start control means actuable for commencing the winding operation, and said control means being connected to said start control means for increasing the yarn tension in response to starting of the winding operation.

5. In a yarn-package winding machine according to claim 3, said Wind-up means comprising a spool-core journalling frame pivotally movable to start-Winding posil tion, and said control means being connected to said frame for increasing the yarn tension in response to movement of said frame to said position during initial Winding of a package for increased frictional adherence of the initial yarn turns to the core.

6. In a yarn-package winding machine according to claim 1, said control means comprising a timing device for discontinuing the increase in yarn tension upon elapse of a given interval of time.

7. A yarn-package Winding machine according to claim 1 comprising a take-up spool exchanging mechanism for automatically replacing a full spool by a new spool core, said control means being connected to said exchange mechanism for increasing the yarn tension in response to insertion of a new core during initial winding of a package for increased frictional adherence of the initial yarn turns to the core.

8. In a yarn-package Winding machine according to claim 1, said wind-up means comprising a spool-core journalling frame pivotally movable to a start-winding position, a take-up spool exchanging mechanism for automatically replacing a full spool by a new spool core on said journalling frame, a damping device linked to said frame for limiting its speed of pivotal movement, said damping device cooperating with said control means for maintaining increased yarn tension for a timed interval beginning when said frame moves to said start position.

References ited by the Examiner UNITED STATES PATENTS STANLEY N. GlLREATH, Primary Examiner. 

1. A YARN-PACKAGE WINDING MACHINE COMPRISING WINDUP MEANS FOR REVOLVING A TUBULAR CORE TO WIND THE YARN THEREUPON, YARN GUIDE MEANS DEFINING A YARN PATH AND HAVING A YARN RECIPROCATING GUIDE MEMBER ADJACENT SAID WIND-UP MEANS FOR RECIPROCATING THE ONCOMING YARN ALONG THE CORE, CONTROLLABLE YARN-TENSIONING MEANS DISPOSED AT SAID PATH FOR ENGAGING THE YARN AND NORMALLY APPLYING SUBSTANTIALLY CONSTANT TENSION THERETO, SAID YARNTENSIONING MEANS HAVING CONTROL MEANS COOPERATING WITH SAID WIND-UP MEANS FOR TEMPORARILY INCREASING THE NORMALLY SUBSTANTIALLY CONSTANT YARN TENSION DURING INITIAL WINDING OF A PACKAGE SO AS TO INCREASE FRICTIONAL ADHERENCE OF THE INITIAL YARN TURNS TO THE CORE. 